Methods for the identification, recognition, or authentication of people from their biometric characteristics are common at the present time. In recognition systems, use can be made of fingerprints, the iris of the eye, the ear, and even the total morphology of the head. However, fingerprints are most commonly used for purposes of recognition.
While the use of fingerprints for identification provides a high level of resolution, it has a large number of drawbacks. For example, because of the considerable amount of information that it can deliver, fingerprinting systems are expensive and slow to operate.
The acquisition of fingerprints involves placing the tip of a finger on a printing surface. However:                the grease or perspiration covering the finger can affect the resulting print;        the contact between the finger and the printing surface can lead to distortions; and        it is relatively easy to cover the finger with a false fingerprint sheath so that it is invisible to an operator.        
In short, the applicant has sought an alternative solution that is more flexible and more rapid than fingerprinting, but is as reliable as fingerprinting for identification purposes.